Combine egg with 1 tablespoon oil and cornstarch in a large bowl. Add chicken pieces and toss gently to coat evenly.

Heat 1/2 cup oil in wok over medium-high heat until haze forms. Add nuts and fry until golden, about 4 to 5 minutes. Be careful, as they burn easily. Drain on paper towels. Add chicken, (in small batches if doubling recipe), and cook until golden and done, about 3 minutes. Drain well.

Pour off all but a thin film of oil. Return pan to heat, add Hoisin Sauce, ginger, sugar, soy sauce, and sesame oil and stir until combined. Reduce heat and simmer, stirring constantly until sauce begins to glisten, about 1 to 2 minutes. Add chicken and nuts and mix thoroughly with sauce. Transfer to serving dish and garnish with green onions.

Notes:

If using more chicken, increase other ingredients accordingly to each additional 1 1/2 pounds of chicken.